Magnesium sulfate in the management of patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study

The role of nimodipine and magnesium sulfate in the prevention and treatment of vascular spasm in patients in the acute rupture of cerebral aneurysms

Vascular spasm in patients with hemorrhage from rupture of cerebral aneurysms is the main cause of adverse outcomes of the disease. One way to treat persistent contraction of cerebral arteries is to use nimodipine and magnesium sulfate. This literature review presents studies on the use of nimodipine and magnesium sulfate in the treatment of vascular spasm, and highlights the main links of pathogenesis and drug action mechanisms.

Magnesium Sulfate Provides Neuroprotection in Eclampsia-Like Seizure Model by Ameliorating Neuroinflammation and Brain Edema

Eclampsia is a hypertensive disorder of pregnancy that is defined by the new onset of grand mal seizures on the basis of preeclampsia and a leading cause of maternal and fetal mortality worldwide. Presently, magnesium sulfate (MgSO₄) is the most effective treatment, but the mechanism by which MgSO₄ prevents eclampsia has yet to be fully elucidated. We previously showed that systemic inflammation decreases the seizure threshold in a rat eclampsia-like model, and MgSO₄ treatment can decrease systemic inflammation. Here, we hypothesized that MgSO₄ plays a neuroprotective role in eclampsia by reducing neuroinflammation and brain edema. Pregnant Sprague-Dawley rats were given an intraperitoneal injection of pentylenetetrazol following a tail vein injection of lipopolysaccharide to establish the eclampsia-like seizure model. Seizure activity was assessed by behavioral testing. Neuronal loss in the hippocampal CA1 region (CA1) was detected by Nissl staining. Cerebrospinal fluid levels of S100-B and ferritin, indicators of neuroinflammation, were detected by enzyme-linked immunosorbent assay, and ionized calcium binder adapter molecule 1 (Iba-1, a marker for microglia) and glial fibrillary acid protein (GFAP, a marker for astrocytes) expression in the CA1 area was determined by immunofluorescence staining. Brain edema was measured. Our results revealed that MgSO₄ effectively attenuated seizure severity and CA1 neuronal loss. In addition, MgSO₄ significantly reduced cerebrospinal fluid levels of S100-B and ferritin, Iba-1 and GFAP activation in the CA1 area, and brain edema. Our results indicate that MgSO₄ plays a neuroprotective role against eclampsia-like seizure by reducing neuroinflammation and brain edema.

Methazolamide improves neurological behavior by inhibition of neuron apoptosis in subarachnoid hemorrhage mice

Subarachnoid hemorrhage (SAH) results in significant nerve dysfunction, such as hemiplegia, mood disorders, cognitive and memory impairment. Currently, no clear measures can reduce brain nerve damage. The study of brain nerve protection after SAH is of great significance. We aim to evaluate the protective effects and the possible mechanism of methazolamide in C57BL/6J SAH animal model in vivo and in blood-induced primary cortical neuron (PCNs) cellular model of SAH in vitro. We demonstrate that methazolamide accelerates the recovery of neurological damage, effectively relieves cerebral edema, and improves cognitive function in SAH mice as well as offers neuroprotection in blood- or hemoglobin-treated PCNs and partially restores normal neuronal morphology. In addition, western blot analyses show obviously decreased expression of active caspase-3 in methazolamide-treated SAH mice comparing with vehicle-treated SAH animals. Furthermore, methazolamide effectively inhibits ROS production in PCNs induced by blood exposure or hemoglobin insult. However, methazolamide has no protective effects in morality, fluctuation of cerebral blood flow, SAH grade, and cerebral vasospasm of SAH mice. Given methazolamide, a potent carbonic anhydrase inhibitor, can penetrate the blood–brain barrier and has been used in clinic in the treatment of ocular conditions, it provides potential as a novel therapy for SAH.

Current controversies in the prediction, diagnosis, and management of cerebral vasospasm: where do we stand?

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 persons in the United States each year. Around 30 percent of patients with aneurysmal subarachnoid hemorrhage suffer from cerebral ischemia and infarction due to cerebral vasospasm, a leading cause of treatable death and disability following aneurysmal subarachnoid hemorrhage. Methods used to predict, diagnose, and manage vasospasm are the topic of recent active research. This paper utilizes a comprehensive review of the recent literature to address controversies surrounding these topics. Evidence regarding the effect of age, smoking, and cocaine use on the incidence and outcome of vasospasm is reviewed. The abilities of different computed tomography grading schemes to predict vasospasm in the aftermath of subarachnoid hemorrhage are presented. Additionally, the utility of different diagnostic methods for the detection and visualization of vasospasm, including transcranial Doppler ultrasonography, CT angiography, digital subtraction angiography, and CT perfusion imaging is discussed. Finally, the recent literature regarding interventions for the prophylaxis and treatment of vasospasm, including hyperdynamic therapy, albumin, calcium channel agonists, statins, magnesium sulfate, and endothelin antagonists is summarized. Recent studies regarding each topic were reviewed for consensus recommendations from the literature, which were then presented.

Magnesium treatment for neuroprotection in ischemic diseases of the brain

This article reviews experimental and clinical data on the use of magnesium as a neuroprotective agent in various conditions of cerebral ischemia. Whereas magnesium has shown neuroprotective properties in animal models of global and focal cerebral ischemia, this effect could not be reproduced in a large human stroke trial. These conflicting results may be explained by the timing of treatment. While treatment can be started before or early after ischemia in experimental studies, there is an inevitable delay of treatment in human stroke. Magnesium administration to women at risk for preterm birth has been investigated in several randomized controlled trials and was found to reduce the risk of neurological deficits for the premature infant. Postnatal administration of magnesium to babies after perinatal asphyxia has been studied in a number of controlled clinical trials. The results are promising but the trials have, so far, been underpowered. In aneurysmal subarachnoid hemorrhage (SAH), cerebral ischemia arises with the onset of delayed cerebral vasospasm several days after aneurysm rupture. Similar to perinatal asphyxia in impending preterm delivery, treatment can be started prior to ischemia. The results of clinical trials are conflicting. Several clinical trials did not show an additive effect of magnesium with nimodipine, another calcium antagonist which is routinely administered to SAH patients in many centers. Other trials found a protective effect after magnesium therapy. Thus, it may still be a promising substance in the treatment of secondary cerebral ischemia after aneurysmal SAH. Future prospects of magnesium therapy are discussed.

Cerebral vasospasm pharmacological treatment: an update

Aneurysmal subarachnoid hemorrhage- (aSAH-) associated vasospasm constitutes a clinicopathological entity, in which reversible vasculopathy, impaired autoregulatory function, and hypovolemia take place, and lead to the reduction of cerebral perfusion and finally ischemia. Cerebral vasospasm begins most often on the third day after the ictal event and reaches the maximum on the 5th-7th postictal days. Several therapeutic modalities have been employed for preventing or reversing cerebral vasospasm. Triple "H" therapy, balloon and chemical angioplasty with superselective intra-arterial injection of vasodilators, administration of substances like magnesium sulfate, statins, fasudil hydrochloride, erythropoietin, endothelin-1 antagonists, nitric oxide progenitors, and sildenafil, are some of the therapeutic protocols, which are currently employed for managing patients with aSAH. Intense pathophysiological mechanism research has led to the identification of various mediators of cerebral vasospasm, such as endothelium-derived, vascular smooth muscle-derived, proinflammatory mediators, cytokines and adhesion molecules, stress-induced gene activation, and platelet-derived growth factors. Oral, intravenous, or intra-arterial administration of antagonists of these mediators has been suggested for treating patients suffering a-SAH vasospam. In our current study, we attempt to summate all the available pharmacological treatment modalities for managing vasospasm.

Intravenous magnesium infusion for the prevention of symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE

The study examined the difference in the incidence of symptomatic cerebral vasospasm with magnesium supplementation in aneurysmal subarachnoid hemorrhage (SAH) in a Korean population.

METHODS

This retrospective analysis was performed in 157 patients diagnosed with aneurysmal SAH from January 2007 to December 2011 at a single center. Seventy patients (44.6%) received a combination treatment of nimodipine with magnesium and 87 patients (55.4%) received only nimodipine. A matched case-control study using propensity scores was conducted and 41 subjects were selected from each group. A dosage of 64 mmol/day of magnesium was administrated.

RESULTS

The infusion of magnesium did not reduce the incidence of symptomatic cerebral vasospasm (n=7, 17.1%, p=0.29) compared with simple nimodipine injection (n=11, 26.8%). The ratios of good clinical outcome (modified Rankin scale 0-2) at 6 months were similar, being 78% in the combination treatment group and 80.5% in the nimodipine only group (p=0.79). The proportions of delayed cerebral infarction was not significantly lower in patients with combination treatment (n=2, 4.9% vs. n=3, 7.3%; p=0.64). There was no difference in the serum magnesium concentrations between the patients with symptomatic vasospasm and without vasospasm who had magnesium supplementation. No major complications associated with intravenous magnesium infusion were observed.

CONCLUSION

Magnesium supplementation (64 mmol/day) may not be beneficial for the reduction of the incidence of symptomatic cerebral vasospasm in patients with aneurysmal SAH.

Magnesium sulfate administration in subarachnoid hemorrhage

Magnesium offers theoretic vascular and neuroprotective benefits for patients with subarachnoid hemorrhage. An electronic literature search was conducted to identify original research studies describing intravenous magnesium treatment in patients with SAH published in English between January 1990 and October 2010. Seventeen articles were identified and reviewed, including one phase III randomized-controlled clinical trial and six phase II randomized-controlled trials. Study quality was low for most of the included studies, with the phase III trial considered to be of moderate quality. Due to inconsistently reported benefits and the occurrence of side effects, phase II data suggested that intravenous magnesium for SAH provided either no overall net benefit or uncertain trade-offs. Benefit was likewise not supported in the single phase III clinical trial.

Intravenous magnesium sulphate for aneurysmal subarachnoid hemorrhage: an updated systemic review and meta-analysis

INTRODUCTION

Previous meta-analyses of magnesium sulphate infusion in the treatment of aneurysmal subarachnoid hemorrhage (SAH) have become outdated due to recently published clinical trials. Our aim was thus to perform an up-to-date systemic review and meta-analysis of published data on the use of magnesium sulphate infusion in aneurysmal SAH patients.

METHODS

A systemic review and meta-analysis of the literature was carried out on published randomized controlled clinical trials that investigated the efficacy of magnesium sulphate infusion in aneurysmal SAH patients. The results were analyzed with regard to delayed cerebral ischemia (DCI), delayed cerebral infarction, and favorable neurological outcomes at three and six months. The risks of bias were assessed using the Jadad criteria, with a Jadad score >3 indicating a lower such risk. Meta-analyses are presented in terms of relative risk (RR) with 95% confidence intervals (CIs).

RESULTS

Six eligible studies with 875 patients were reviewed. The pooled RR for DCI was 0.87 (95% CI, 0.36 to 2.09; P = 0.75). That for delayed cerebral infarction was 0.58 (95% CI, 0.35 to 0.97; P = 0.04), although this result did not persist if only randomized clinical trials with a lower risk of bias were included (RR 0.61, 95% CI, 0.31 to 1.22; P = 0.17). The pooled RR for a favorable outcome at three months was 1.14 (95% CI, 0.99 to 1.31; P = 0.07), and that for a favorable outcome at six months was 1.08 (95% CI, 0.94 to 1.24; P = 0.29).

CONCLUSIONS

The present findings do not lend support to a beneficial effect of magnesium sulphate infusion on delayed cerebral infarction. The reduction in DCI and improvement in the clinical outcomes of aneurysmal SAH patients following magnesium sulphate infusion observed in previous pilot studies are not confirmed, although a beneficial effect cannot be ruled out because of sample size limitation.

Clinical review: Prevention and therapy of vasospasm in subarachnoid hemorrhage

Vasospasm is one of the leading causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Radiographic vasospasm usually develops between 5 and 15 days after the initial hemorrhage, and is associated with clinically apparent delayed ischemic neurological deficits (DID) in one-third of patients. The pathophysiology of this reversible vasculopathy is not fully understood but appears to involve structural changes and biochemical alterations at the levels of the vascular endothelium and smooth muscle cells. Blood in the subarachnoid space is believed to trigger these changes. In addition, cerebral perfusion may be concurrently impaired by hypovolemia and impaired cerebral autoregulatory function. The combined effects of these processes can lead to reduction in cerebral blood flow so severe as to cause ischemia leading to infarction. Diagnosis is made by some combination of clinical, cerebral angiographic, and transcranial doppler ultrasonographic factors. Nimodipine, a calcium channel antagonist, is so far the only available therapy with proven benefit for reducing the impact of DID. Aggressive therapy combining hemodynamic augmentation, transluminal balloon angioplasty, and intra-arterial infusion of vasodilator drugs is, to varying degrees, usually implemented. A panoply of drugs, with different mechanisms of action, has been studied in SAH related vasospasm. Currently, the most promising are magnesium sulfate, 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, nitric oxide donors and endothelin-1 antagonists. This paper reviews established and emerging therapies for vasospasm.

Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage: An Overview of Pharmacologic Management

Cerebral vasospasm remains one of the leading causes of mortality in patients who experience a subarachnoid hemorrhage but survive the initial 24 hours. Vasospasm generally occurs 3-4 days after the initial subarachnoid hemorrhage and peaks at 5-7 days. The pathophysiology of vasospasm is poorly understood, which directly contributes to the inconsistency of management and creates a formidable challenge in clinical practice. Traditionally, hemodilution, hypervolemia, and induced hypertension (so-called triple H therapy); calcium channel blockers; and endovascular therapy have been used as either prophylactic therapy or treatment. However, management of vasospasm varies among physicians and institutions mainly because of a lack of large clinical trials and inconsistent results. Practice has been based primarily on case reports and the preference of each practitioner. Several experimental therapies have been explored; however, large, prospective, randomized controlled trials are needed to elucidate the role of these therapies.

Extracerebral organ dysfunction in the acute stage after aneurysmal subarachnoid hemorrhage

In patients with aneurysmal subarachnoid hemorrhage (SAH), secondary complications are an important cause of morbidity and case fatality. Delayed cerebral ischemia and hydrocephalus are important intracranial secondary complications. Potentially treatable extracranial complications are also frequently observed, and some are related to the occurrence of delayed cerebral ischemia and outcome. In addition to the occurrence of an inflammatory response and metabolic derangements, cardiac and pulmonary complications are the most common extracranial complications. This article provides an overview of the most common extracranial complications in patients with SAH and describes their effects on outcome and delayed cerebral ischemia.

Dose evaluation for long-term magnesium treatment in aneurysmal subarachnoid haemorrhage

BACKGROUND

Magnesium is a neuroprotective agent that might prevent or reverse delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage (SAH). We are presently running a randomized, placebo-controlled, double blind trial with magnesium sulphate (64 mmol/day intravenously). We studied whether this treatment regime resulted in our target serum magnesium levels of 1.0-2.0 mmol/L.

METHODS

Magnesium sulphate was administered intravenously as soon as possible after admission and continued until 14 days after occlusion of the aneurysm. Serum magnesium measurements were done at baseline and at least every 2 days during administration of trial medication. For comparison we used the serum magnesium levels of the placebo-treated patients.

RESULTS

Magnesium therapy was begun in 94 patients. The mean magnesium level in the treatment period was 1.47 +/- 0.32 mmol/L. In 81 patients serum magnesium stayed within target levels during the entire treatment period. One patient had a serum magnesium level below 1.0 mmol/L (0.91 mmol/L) in a single measurement and 10 patients had serum magnesium levels above 2.0 mmol/L at one or more measurements. In six patients magnesium therapy was discontinued: in three because of nausea, headache, or both in combination with serum magnesium levels above 2.0 mmol/L and in the other three because of hypotension, phlebitis and renal failure.

CONCLUSIONS

With an intravenous dosage schedule of 64 mmol magnesium sulphate a day, serum magnesium levels of 1.0-2.0 mmol/L can easily be maintained without severe side effects for an extended period in a vast majority of patients with SAH.

Serum magnesium levels as related to symptomatic vasospasm and outcome following aneurysmal subarachnoid hemorrhage

INTRODUCTION

Recent evidence suggests that magnesium may be neuroprotective in the setting of cerebral ischemia, and therapeutic magnesium infusion has been proposed for prophylaxis and treatment of delayed ischemic neurological deficit (DIND) resulting from vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). We studied the association between serum magnesium levels, the development of DIND, and the outcomes of patients with SAH.

METHODS

We studied 128 consecutive patients with aneurysmal SAH treated at our institution between 1990 and 1997 who had a serum magnesium level measured at least once during the acute phase of their hospitalization. Delayed ischemic neurological deficit was defined as severe (major focal deficit or coma), moderate (incomplete focal deficit or decreased sensorium without coma), or none.

RESULTS

There was no significant difference in mean, minimum, or maximum serum magnesium levels between patients with and without DIND (1.93, 1.83, 2.02 versus 1.91, 1.84, 1.97 mg/dL, respectively). Similarly, no difference was found in mean serum magnesium levels among patients with severe (1.94 mg/dL), moderate (1.92 mg/dL), or no DIND (1.91 mg/dL). Analyses of serum magnesium levels before (0-4 days following SAH), during (4-14 days following SAH), and after (greater than 14 days following SAH) the period of highest risk for vasospasm revealed no association with the development or severity of DIND. Permanent deficit or death resulting from vasospasm and Glasgow Outcome Scale score at longest follow-up were similarly unaffected by serum magnesium levels overall or during any time interval. Forty (31.5%) patients were hypomagnesemic (less than 1.7 mg/dL) during hospitalization, but no difference in outcome (p = 0.185) or development of DIND (p = 0.785) was found when compared to patients with normal (1.7-2.1 mg/dL) or high (greater than 2.1 mg/dL) magnesium serum levels.

CONCLUSION

We identified no relationship between serum magnesium levels and the development of DIND or outcome following aneurysmal SAH. Based on these data, magnesium supplementation to normal or high-normal physiological ranges seems unlikely to be beneficial for DIND resulting from vasospasm. However, no inference can be made regarding the value of therapeutic infusion of magnesium to supraphysiological levels.

Cerebral vasospasm: results of a structured multimodal treatment

Symptomatic cerebral vasospasm (CVS) with delayed ischemic neurologic deficits affects about one third of the patients after aneurysmal subarachnoid hemorrhage (SAH). In spite of the lack of definite evidence of large clinical trials, the devastating outcome of the natural history of symptomatic CVS demands an aggressive CVS treatment in a practically oriented, structured multimodal treatment regimen. With our treatment protocol good functional outcome could be reached in 66% of the patients with symptomatic CVS. This policy requires close and fast multidisciplinary collaboration between neurosurgeons, neuroradiologists, competent in endovascular interventions, and specialists for neurointensive care. We report on our experience with 79 cases with symptomatic CVS and delayed ischemic neurologic deficit (DIND) after aneurysmal SAH. The different treatment options with CVS are reviewed and practical guidelines for a step by step treatment are given.

Intravenous magnesium sulfate to improve outcome after aneurysmal subarachnoid hemorrhage: interim report from a pilot study

OBJECTIVES

Magnesium sulfate (MgSO4) may be useful in preventing neurological injury after subarachnoid haemorrhage (SAH). In this randomized, double-blind study we evaluated the safety and efficacy of MgSO4 infusion to improve clinical outcome after aneurysmal SAH.

METHODS

With ethics committee approval and informed consents, 45 patients with SAH were randomly allocated to receive either MgSO4 80 mmol/day or saline infusion for 14 days. All patients also received intravenous nimodipine. Episodes of vasospasm were treated with hypertensive, hypervolemic therapy. Neurological status was assessed 3 months after haemorrhage using Barthel index and Glasgow outcome scale (GOS). Incidences of cardiac and pulmonary complications were also recorded. Data were compared between groups using Mann-Whitney or Fisher exact tests as appropriate. P < 0.05 was considered significant.

RESULTS

Patient characteristics, severity of SAH and surgical treatment did not differ between groups. Although the number of episodes was not reduced, MgSO4 shortened the duration of vasospasm. Patients receiving MgSO4 tended to have fewer neurological deficits, better functional recovery and an improved score in GOS. However, none of these outcome variables reached statistical significance. The incidence of cardiac and pulmonary complications in the MgSO4 group (43%) was also similar to that in the saline group (59%), P = 0.14.

CONCLUSIONS

MgSO4 infusion after aneurysmal SAH is well tolerated and may be useful in producing better outcome. A larger study is required to confirm the neuroprotective effect of MgSO4.

Cerebral Vasospasm Following Subarachnoid Hemorrhage

Cerebral vasospasm and related ischemic stroke continue to be significant complicating factors in the course of many patients with subarachnoid hemorrhage from berry aneurysm rupture. The risk of this well-recognized but poorly understood complication can be estimated on the basis of patient medical history, neurologic examination, and head CT findings. Every patient with possible risk needs specialized neurologic intensive care unit care after aneurysm obliteration. Surgical and pharmacologic wash-out of subarachnoid blood around the basal arteries, proper management of intracranial pressure and fluid status, hyponatremia, hypomagnesemia, and fever, as well as use of calcium channel blockers, have been considered helpful in patient management prior to and with the symptomatic vasospasm development. Transcranial Doppler (TCD) ultrasound is important in detecting vasospasm before the patient suffers ischemic neurologic deficit or infarct. Elevated TCD velocities often initiate the use of triple-H (HHH: hypertension, hemodilution, and hypervolemia) therapy and subsequently guide it. Up to the end of the first 3 weeks after subarachnoid hemorrhage and aneurysm obliteration, development of any focal neurologic deficit or mental deterioration, unless convincingly proven otherwise, is assumed to be from cerebral vasospasm. When a hemodynamically significant vasospasm in the arterial segments of clinical concern is suggested, emergency cerebral angiography with balloon dilatation angioplasty or intra-arterial infusion of vasodilating agents may be helpful in relieving ischemic symptoms.

Cerebral blood flow velocity response to magnesium sulfate in patients after subarachnoid hemorrhage

Magnesium sulfate therapy, standard in preventing seizures in preeclampsia, is under active investigation as a neuroprotective agent. The authors studied the effect of magnesium as a cerebral vasodilator by measuring the cerebral blood flow velocity (CBFV) response to a 5g intravenous bolus of MgSO4 compared with a saline placebo after subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasonography of the middle cerebral artery (MCA) was measured after each infusion. Patients were studied up to three times after SAH at prescribed time intervals. Fourteen patients (11 women, 3 men; mean age 58 years) underwent 29 studies. All patients underwent hypertensive, hypervolemic therapy. Four patients developed cerebral vasospasm. Doubling serum magnesium levels did not affect MCA CBFV but slightly lowered mean arterial blood pressure and systemic vascular resistance. Intravenous magnesium bolus did not reduce elevated CBFV in the subset of SAH patients with clinical vasospasm. The role of magnesium sulfate as a cerebral vasodilator in patients with SAH requires further study.